System for producing margarine



Feb. 10, 1970 L. A. BONDESSON ETAL 3,494,275

SYSTEM FOR PRODUCING MARGARINE Filed June 4, 1968 I N VE N TORS United States Patent 3,494,275 SYSTEM FOR PRODUCING MARGARINE Lennart Adolf Bondesson, Bandhagen, and Hilding Sven Svensson, Tumba, Sweden, assignors to Alta-Laval AB, Tumba, Sweden, a corporation of Sweden Filed June 4, 1968, Ser. No. 734,439 Claims priority, application Great Britain, June 7, 1967, 26,355/67 Int. Cl. A23d 3/02 US. Cl. 99244 2 Claims ABSTRACT OF THE DISCLOSURE When the margarine coming from the cooler in solidified form is not immediately packaged, it is returned through a closed path so that it passes again through at least part of the production system, the closed return path comprising a pre-heater in the form of a tube heat exchanger, or the like, and a melting apparatus in the form of a plate heat exchanger for receiving the preheated margarine.

In the usual system for producing margarine, water, fat and other substances, such as vitamins, lactic acid, salts, etc., are mixed to for an emulsion which is first heated to a pre-determined temperature in a heat exchanger and is then cooled in a cooler especially adapted for the purpose. The margarine leaving the cooler is then packed by means of a packaging machine.

Unfortunately, faults occur rather often in the packaging machines if a system for production of margarine. This means that all of the margarine leaving the coolers cannot be packaged immediately. To enable the coolers to be kept running continuously, even when small faults arise in any of the packaging machines, a vessel is usually provided in the system for collecting margarine that cannot be packaged by the packaging machines. Margarine collected in a vessel of this kind is melted be heating means arranged in the vessel and is then returned to the system and cooled in order to re-solidify the margarine.

The equipment heretofore used for melting and returning margarin by-passing the packaging machines has certain drawbacks. For example, the margarine undergoing melting in the vessel is subjected not only to an undesired oxidation but also to rather great risks of infection, since this vessel is constantly open to the surrounding atmosphere.

The principal object of the present invention is to eliminate these drawbacks, which have long been recognized in the art of margine production. This object is achieved by providing the system with means for returning through a closed path the margarine that is not immediately packed by the packaging machines, so that it will again pass through all or part of the system, the closed returning means comprising a pro-heater in the form of a tube heat exchanger, or the like, and a melting apparatus in the form of a plate heat exchanger.

From the economic point of view, a plate heat exchanger is deemed to be the only kind of heat exchanger which could be considered for the above-noted purpose of melting the returning margarine. However, a plate heat exchanger is not easily adaptable for this purpose. It has proved quite impossible to introduce cold (that is, solid) margarine directly into a plate heat exchanger. Several experiments have been made in attempting to utilize a plate heat exchanger as a melting apparatus for margarine, but these experiments have not been successful until the advent of the present invention.

Fee

The invention is described in detail below with reference to the accompanying drawing, in which the single illustration is a diagrammatic view of a margarine producing system constructed according to the invention.

In the illustrated system, water, fat, lactic acid, salts, vitamins, etc., are introduced at A. These substances are mixed in a conduit 1 to form an emulsion which passes through a non-return valve 2 to a pump 3 and thence through a plate heat exchanger 4. In the plate heat exchanger, the emulsion is heated to about 38 C. By means of a number of high pressure pumps 5, the emulsion is then pumped to a number of coolers 6 wherein finished margarine is formed. The margarine leaving the coolers 6 has a temperature of about 15 C. and is consequently in a solid state. From these coolers, the finished margarine is pumped by means of the high pressure pumps 5 to a number of packaging machines 7, from which it is normally discharged in packages at B.

If the packaging machines 7 for some reason are unable to package all the margarine leaving the coolers 6, the margarine is pumped into one or more conduits 8. Conduits 8 are surrounded along part of their length by sleeve-like jackets 9 through which hot water is passed by way of suitable inlets and outlets (not shown). In its passage through each jacket 9, the margarine flowing through the corresponding conduit 8 is heated only at its surface layer. This is sufiicient for enabling the margarine to be introduced into a plate heat exchanger 10 without obstructions, the margarine being melted to a liquid state in the exchanger 10.

The high pressure pumps 5 are used for pumping the margarine through conduits 8 as well as through plate heat exchanger 10.

From the plate heat exchanger 10, the margarine is returned to conduit 1 at the inlet side of pump 3 but at the outlet side of non-return valve 2. In this way, it is caused to flow again through plate heat exchanger 4 and coolers 6.

Due to the above described arrangement, none of the coolers 6 needs to be taken out of operation if a small fault should occur in any of the packaging machines 7. The production process may go on continuously and, more particularly, in such a manner that margarine which cannot be packaged immediately, after having been cooled to a solid state, is returned to the production system in a liquid state without having come into contact with the surrounding atmosphere. Oxidation and infections are thereby prevented.

As shown in the drawing, the connection leading from each cooler 6 is provided with a valve 6a operable to direct the solidified margarine selectively to either the corresponding packaging machine 7 or the corresponding return conduit 8. Also, the plate heat exchanger 10 is shown with an inlet Illa and an outlet 10!; for the heating medium, whereby the latter flows through the heat exchanger in the same direction as the margarine from pre-heaters 9'.

We claim:

1. In combination with a margarine producing system comprising means for supplying an emulsion, a cooler connected to said supply means for solidifying the emulsion to form solid margarine, a machine for packaging solid margarine, and a connection between the cooler and the packaging machine for transmitting solid margarine to said machine, said system including a first closed flow path for the emulsion, means forming a second closed path leading from said connection for receiving margarine not immediately packaged by said machine and returning the unpackaged margarine to a point in said first closed flow path for passage again through at least part of the system, said closed return path including a pre-heater in the form of a tube heat exchanger and a melting apparatus in the form of a plate heat exchanger connected to receive margarine from the pre-heater.

2. The combination according to claim 1, in which said plate heat exchanger is arranged for passage of a heating medium therethrough in the same direction as the margarine.

' References Cited UNITED STATES PATENTS 2,353,3-82 7/1944 Barrett 165-66XR Hytte 165-66 Thompson 16566 Elwood et al. 99--122 Elwood et al. 99244 McCuiston 99'234 Froelich 16566 WALTER A. SCHEEL, Primary Examiner 0 ARTHUR O. HENDERSON, Assistant Examiner 

